Stimulating outperformance has been increasingly emphasized in educational policies. Although personally satisfying, outperformance can also lead to interpersonal strain, which is often overlooked in the educational excellence discourse. Exline and Lobel (1999, "Psychological Bulletin, 125"(3), 307-337) coined Sensitivity about being the Target of a Threatening Upward Comparison (STTUC) to refer to this outperformance-related distress. STTUC has been primarily studied in adults. This article consists of two studies (N = 92 and N = 246) evaluating emotional responses to outperforming others in 9 to 12-year-olds. By means of a scenario-based measure (C-TROO), we examined the relationship between these responses and the personality characteristics sociotropy, narcissism and circular thinking. We found that negative emotions as measured by the C-TROO are linked to sociotropy and C-TROO's positive emotions to narcissism, mirroring adult's responses to outperformance. Additionally, circular thinking correlates positively to negative emotions and negatively to positive emotions. The present study shows that children aged 9-12 can experience Sensitivity about being the Target of a Threatening Upward Comparison (STTUC) and that this sensitivity follows the same nomological network in children as in adults. Because children high on sociotropy are more likely to experience STTUC, and those high on narcissism do not suffer from STTUC but see outperforming as a positive experience, educational excellence policies can have unforeseen repercussions.